Power systems, such as, for example, internal combustion engines output a substantial amount of power and, in doing so, also generate a large amount of heat. If not properly controlled, this heat could damage the engine or result in inefficient operation of the engine. Fluid cooling systems are often used to transfer heat from the engine, thereby increasing the life and efficiency of the engine. A typical fluid cooling system includes a pump to circulate a cooling fluid through the engine, a motor drivingly coupled to the pump, and a controller to regulate operation of the motor. The cooling capacity of the cooling system ultimately depends on the motor. Inadequate heat dissipation from the motor may limit the amount of torque output of the motor, which may limit the amount of cooling fluid that the pump can circulate.
One method to dissipate heat from a motor associated with a cooling system is described in U.S. Pat. No. 6,702,555 (hereinafter referred to as “the '555 patent”) issued to Allen et al. on Mar. 9, 2004. The '555 patent discloses a fluid pump with a diffuser, a stator disposed within a diffuser cavity, a tubular member isolating the diffuser from a working fluid flowing through the fluid pump, a rotor disposed within the tubular member for driving an impeller, and a controller disposed within the diffuser. The motor of the '555 patent drives a pump for circulating the working fluid through the pump. The circulation of fluid around the diffuser-contained motor and controller provides for improved heat transfer, and the integrated motor/pump configuration may reduce the number of interconnections required to operate separate pump and motor units.
Although the pump of the '555 patent may improve motor heat dissipation, it may still remove an insufficient amount of heat from the motor. For example, because the motor and controller are located within the diffuser and isolated from the working fluid, heat dissipation may be substantially hindered by the diffuser wall. Furthermore, the configuration of the system of the '555 patent may not provide adequate regulation of the flow rate of the pump. For example, the system of the '555 patent is not configured to monitor the temperature of the motor or the working fluid and adjust flow rate of the pump in accordance with the monitored temperature. As a result, because control of the flow rate of the pump is independent of motor temperature, additional heat generated by the motor may not be adequately extracted, which may result in inefficient and/or inadequate operation of the motor.
In addition, the system of the '555 patent may lack monitoring and control capabilities. For example, the controller of the '555 patent is not configured to monitor the operational characteristics (e.g., temperature, pressure, etc.) of either the motor or the working fluid and control the motor/pump in response to the monitored characteristics. Thus, should the motor or working fluid operational characteristics exceed a specified threshold, the '555 patent may not provide the necessary response to ensure appropriate operation of the cooling system. Furthermore, because flow rate is not controlled based on the cooling needs of the motor, the system of the '555 patent may still be prone to motor overheating.
The presently disclosed integrated cooling system and method are directed toward overcoming one or more of the problems set forth above.